diff --git a/dev/tools/phan/config_fixer.php b/dev/tools/phan/config_fixer.php
index 11daf743c09..056a5c26805 100644
--- a/dev/tools/phan/config_fixer.php
+++ b/dev/tools/phan/config_fixer.php
@@ -176,6 +176,8 @@ return [
 	// Add any issue types (such as 'PhanUndeclaredMethod')
 	// here to inhibit them from being reported
 	'suppress_issue_types' => [
+		'PhanCompatibleNegativeStringOffset',	// return false positive
+
 		'PhanPluginWhitespaceTab',		// Dolibarr used tabs
 		'PhanPluginCanUsePHP71Void',	// Dolibarr is maintaining 7.0 compatibility
 		'PhanPluginShortArray',			// Dolibarr uses array()